1. Field of the Invention
Aspects of the present invention relate to an organic light emitting display and a method of manufacturing the same
2. Description of the Related Art
Recently, various flat panel displays, which have a light-weight and a small-volume as compared to cathode ray tubes (CRT), have been developed. In particular, organic light emitting display devices, which have excellent emission efficiency, luminance, viewing angle, and response speed, have been highlighted.
An organic light emitting display displays an image by using a plurality of organic light emitting diodes (OLED). An OLED includes an anode electrode, a cathode electrode, and an organic emission layer. The organic emission layer is disposed between the anode electrode and the cathode electrode and emits light by a combination of electrons and holes.
The organic light emitting display displays a high brightness, if a large amount of current flows in its organic light emitting diodes, and displays a low brightness, if a small amount of current flows in its organic light emitting diodes. Gradation levels are controlled by the amount of current amount flowing in the organic light emitting diodes.
At the same applied voltage, different organic light emitting displays produce different brightness levels, because the current flowing in the organic light emitting diodes varies, according to the manufacturing processes used to produce the organic light emitting displays.
FIG. 1 is a graph showing brightness distribution of a related art organic light emitting displays. Referring to FIG. 1, the horizontal axis shows brightness levels, the vertical axis shows quantity (numbers of displays), and the dotted line shows a standardized normal range.
When measuring a brightness of the organic light emitting displays, the displays can each have a different brightness, thereby filling the brightness distribution illustrated in FIG. 1. A brightness of around 150 is a targeted level, and a brightness ranging between 128 and 172 is determined to be the normal range.
The organic light emitting displays in the normal range have no restriction on use, since users may not notice a brightness difference. However, the organic light emitting displays having a brightness outside of the normal range display images that are too dark or images that appear washed out. Therefore, the visibility of such displays is poor, and proper images are not displayed, causing such displays to be undesirable.